----------------------------------- jonos Wed Feb 18, 2004 6:25 pm cos and sin ----------------------------------- i have seen these used a lot, and if its not too much trouble, could someone please explain these and what they do. im only starting grade 10 math, so i don't know. ----------------------------------- Paul Wed Feb 18, 2004 6:54 pm ----------------------------------- They're used in trig, you can use them in solving for parts of a triangle if certain other parts are known. I think only in right angeled triangles: sin(angle) = opposite / hypotenuse cos(angle) = adjacent / hypotenuse haven't reached that unit yet, remebered from some book 2 summers back... that I was made to study... ----------------------------------- Tony Wed Feb 18, 2004 7:06 pm ----------------------------------- Sin/Cos/Tan are ratios formed between the sides of the triangle in relation to an angle. If you know an angle and 1 side, you can find all other sides using trig. Sin/Cos/Tan functions are applied to the right angle triangle, but you can use special ratios in any triangle. a^2 = b^2 + c^2 - 2bc CosA where a,b,c are the sides and A is the angle opposite of the side a also SinA/a = SinB/b = SinC/b ----------------------------------- jonos Wed Feb 18, 2004 7:27 pm ----------------------------------- thanks for explaining it, but is there any where where i could get a more simpler definition/use ----------------------------------- Tony Wed Feb 18, 2004 8:26 pm ----------------------------------- grade 10 math textbook :lol: ----------------------------------- shorthair Wed Feb 18, 2004 9:25 pm ----------------------------------- its hte final unit in math , it makes the course relaxing after quadratices, good way to end hte year / semester ... trignometry is fun and good for programming ----------------------------------- Tony Wed Feb 18, 2004 9:55 pm ----------------------------------- trig is neccessary for programming :lol: lol, quadratics... that's the easy stuff... just wait till calculus :lol: ----------------------------------- shorthair Wed Feb 18, 2004 10:02 pm ----------------------------------- in in funtions and relations right now , caculus isnt that dificult ( begginers 0 i was looking at it online couple weeks ago the coursse in grade 12 dosent go very indepth ----------------------------------- Tony Wed Feb 18, 2004 10:07 pm ----------------------------------- well at first its advanced functions... you don't get into the real calculus for a while... but apparently its really useful in physics pass highschool ----------------------------------- Catalyst Wed Feb 18, 2004 10:08 pm ----------------------------------- calculus isnt that hard (it still is fairly hard tho) ----------------------------------- shorthair Wed Feb 18, 2004 10:10 pm ----------------------------------- i quite like functions , i love number secuences aswell in math , the fibionacci geometric and arithmeic i have found very useful ----------------------------------- octopi Thu Feb 19, 2004 12:45 am ----------------------------------- Calculus was hard. Algebra is hard. I love both of them Data Management is a boring pain in the neck. ----------------------------------- Catalyst Thu Feb 19, 2004 7:04 am ----------------------------------- well said ----------------------------------- AsianSensation Thu Feb 19, 2004 7:51 am ----------------------------------- Data Management is a boring pain in the neck. that's why you take it in gr 11 so you won't be bored as much as you would in gr 12. But's Finite is a good course to take, very useful in solving problems. Yeah, I know, with computer science, you could just write up a program and do a probability question by repeatedly running that program, but the matrices and probablity theory you learn is not bad at all, and very very useful. ----------------------------------- apomb Tue Feb 24, 2004 6:43 pm ----------------------------------- I was wondering if Geometry/Discrete Math is useful for programming ... and if it is / not ... what does it teach you ? ----------------------------------- Paul Tue Feb 24, 2004 6:58 pm ----------------------------------- lol, all I know about that course is I have to take it, and its supposably the most difficult math course in the ontario high schools. ----------------------------------- Maverick Tue Feb 24, 2004 10:30 pm ----------------------------------- Thats an affirmative on that. Yes discrete math is good for prog, cause it teachs you angles and all the shiz, along with physics ----------------------------------- jonos Wed Feb 25, 2004 4:43 pm ----------------------------------- what's discrete math... whats the source code? is that the 3u math course, because that is the hardest grade 11 math course and everyone is saying it's really hard and how they had to get a tutor to just get 75% in it. is it really that hard? ----------------------------------- Maverick Wed Feb 25, 2004 4:45 pm ----------------------------------- Well ppl who need tutors shuldnt be taking U courses. No that is 4U, at my school at least. ----------------------------------- Paul Wed Feb 25, 2004 5:09 pm ----------------------------------- Hehe, its MGA 4UI I think (grade 12), and tutors are useless, me excluded :D, one person I tutored went from 60% to 85% :D. But I'm in grade 10 and I have 102%, though it only shows 100 on the report card :( I'll have to take AP calculus along with MGA course in grade 12, along with chemistry and physics, its cause I'm asian (my parents will whip me) and I wanna go into engineering. :D ----------------------------------- Maverick Wed Feb 25, 2004 6:59 pm ----------------------------------- You know you're a |\|ERD when ^^^^^ 102% WTF is that? What course? ----------------------------------- zylum Wed Feb 25, 2004 7:01 pm ----------------------------------- lol, it's not that hard to get over 100% in grade 10 math... ----------------------------------- Maverick Wed Feb 25, 2004 7:04 pm ----------------------------------- Uhh. K, best mark in grade 10 for us was 98%. Hmm i got 72% but math is the root of all evil, and i never studied or did homework. ----------------------------------- jonos Wed Feb 25, 2004 8:07 pm ----------------------------------- no one in my school can get over 99 because no one is perfect, even if they get perfect on tests. no one's communication marks should be perfect because that is not possible how they have it set up. the highest mark was around 93% and i was one mark below that, but i don't see how people can get over 100% because the way it is set up at my school it's impossible. even if you get close to that on all the test, you still can't get over 95%. some schools are just weird. ----------------------------------- Paul Wed Feb 25, 2004 8:23 pm ----------------------------------- Bonus :D extra credit, ez too. No stupid and careless mistakes either ----------------------------------- Maverick Wed Feb 25, 2004 9:28 pm ----------------------------------- Still 102%. holy crap. ----------------------------------- Acid Thu Feb 26, 2004 10:34 am ----------------------------------- SinA/a = SinB/b = SinC/c Not to be anal-retentive, but you got that backwards. a/SinA = b/SinB = c/SinC Another use for these functions is when studying waves. Light and alternating current electricity are examples of sinusoidal waves. ----------------------------------- apomb Thu Feb 26, 2004 4:33 pm ----------------------------------- It doen's Matter what way you put it!!! they still come out to be the same thing! Only its kinda easier to use SinA/a = SinB/b = SinC/c when finding an angle and a/SinA = b/SinB = c/SinC when finding sides. ----------------------------------- thegoose Mon Jun 21, 2004 10:25 am ----------------------------------- Trig problems generally don't appear on computational geometry problems. Instead, vectors seem to be favored by some recent contests a lot. This is probably because trig generates ugly real numbers while vector still can keep everything as integers. ----------------------------------- Cervantes Mon Jun 21, 2004 3:10 pm ----------------------------------- You know you're a |\|ERD when ^^^^^ 102% WTF is that? What course? hey! back off! I'm getting 102% also :lol: but really, 102 isn't all that great. thats a 93 before being multiplied by 1.1. my friend is getting 108%. :lol: ----------------------------------- Paul Mon Jun 21, 2004 5:39 pm ----------------------------------- Person who won math award for the grade: 126% :shock: did NOT know that was possible. ----------------------------------- Cervantes Mon Jun 21, 2004 7:40 pm ----------------------------------- wow. that's a lot. :? what was his mark multiplied by to get there?! this is getting a bit offtopic, so ill bring it back. :) Cervantes to the rescue. using trig, how would you go about creating a program that has a ball sitting on a ramp and, when pressing the arrow keys, the ramp angles itself up or down. then, depending on how the ramp is angled, the ball rolls down it at the proper speed, according to the laws of physics. in case anyone didn't understand my blurb, it should look something like this: http://members.lycos.co.uk/iiharlssoabwd/ball_on_ramp.jpg ----------------------------------- Tony Mon Jun 21, 2004 8:01 pm ----------------------------------- i hope this helps figure out Fx and Fy... and that's what you apply to the ball http://www.compsci.ca/v2/download.php?id=1867 ----------------------------------- Cervantes Tue Jun 22, 2004 7:48 am ----------------------------------- oops, I probably should have mentioned that I've already done this, and am asking how you guys would do it. I sort of cheated. In my program the ball doesn't roll down the slope so much as makes tiny bounces all the way down it. tony, the green line in your drawing, is that the path of the ball if it were not to hit the slope? sorry I don't really understand your drawing :? ----------------------------------- zylum Tue Jun 22, 2004 1:58 pm ----------------------------------- the normal (the green line) is just a perpindicular line to the slope ----------------------------------- Tony Tue Jun 22, 2004 5:06 pm ----------------------------------- normal force is the force that the slope applies to the ball. Fx is the force which pushes the ball to the side Fy is the force with which the ball is being pushed vertically up. But when added with the Fg (gravity), then theoretically the ball should be kept rolling on the slope ----------------------------------- GlobeTrotter Tue Jun 22, 2004 6:02 pm ----------------------------------- I tried to put an example together, are these the right mathematics? setscreen ("graphics:400,400;offscreenonly") var mx, my, mb : int var pointx, pointy : array 1 .. 2 of int var clicked : int var x, y, vx, vy, grav : real := 0 var collision : boolean := false var m, b : real x := 200 y := 120 grav := 0.001 pointx (1) := 0 pointy (1) := 100 pointx (2) := 400 pointy (2) := 100 loop cls mousewhere (mx, my, mb) drawline (pointx (1), pointy (1), pointx (2), pointy (2), 7) drawoval (pointx (1), pointy (1), 5, 5, 7) drawoval (pointx (2), pointy (2), 5, 5, 7) drawfilloval (round (x), round (y), 10, 10, 4) if round (Math.Distance (pointx (1), pointy (1), mx, my))